2. turbine (n.)
– machine with blades that move because of air, water, or steam

Example: Strong winds make the turbine spin faster.

3. disturb (v.)
– to change the usual arrangement or position of something

Example: Global warming disturbs the weather, making one area
have too much rain and another have too little.

4. settle (v.)
– to move downward or fall to reach a surface

Example: He watched the stone settle to the bottom of the river.

5. drought (n.)
– a long period of time with no rain

Example: Farmers and their
crops suffered the most because of the drought.

ArticleRead
the text below.

Wind farms provide clean
energy. Theywork best at night
when winds blow the strongest, complementing
solar panels, which absorb energy during the day. But one study suggests
wind farms may actually warm the earth’s surface up.

According to the study, wind turbinesdisturb the natural flow of cool and warm air. At night, cool air
normally settles on land and helps
cool the earth’s surface. However, wind turbines mix cool and warm air
together, reducing the cooling effect.

Researchers
studied data from 2003 to 2011 satellite readings taken over certain wind
farms in Texas, which is home to the four largest wind farms in the world.
Results showed a total increase of 0.72 degrees Celsius in the said areas.

Professor
Liming Zhou, author of the study, explains that as the numbers and sizes of
wind farms increase, their impact on local weather conditions also increases.

In
Texas, where the number of turbines has jumped from 111 to 2358 in eight
years, farmers have experienced severe droughts.
The droughts have created a significant threat to Texas’ economy, in which agriculture
contributes $80 billion.

However,
Zhou admits there might be some errors in the satellite readings. He hopes to
improve the study by observing wind farms in other parts of the world.

Meanwhile,
many other scientists believe using wind turbines is not harmful. They say a large
number of wind turbines could slightly change air patterns, but would not
create global warming effects similar to those of dangerous gases.

Viewpoint DiscussionEnjoy
a discussion with your tutor.
Discussion A

·After reading the article, did your opinion
about wind power or clean energy change? Why or why not?

· Is
finding alternative or clean sources of energy an important issue in your
country? Please explain your answer.

Discussion B

·Have you noticed strange weather changes in
your country over the years (e.g., increasing rain in the summer, warmer
winters, etc.)? Please explain your answer.

·How do you think global warming affects the
local community where you live?